The first time I heard a grid pool described, my father was coming home with a pocketful of bills he'd just won down at his favorite watering hole. Essentially you make a 10-by-10 grid, strip numbers vertically and horizontally, buy a square, and if the last digit of the score matches your square, you win the money.

But you risk money, right? You can win it or lose it. How is that not gambling?

It's not gambling. It's just people getting together and agreeing to redistribute their money.

You can imagine how long this discussion could go on with a 12-year-old who suspects his old man is full of it. I suppose by his logic home poker games and shooting dice on the corner also don't constitute gambling—heck, they're really no more gambling than paying your taxes! But then, nothing seems like gambling when you win. It's like the old saw for when a bass wriggles off your line: That's why it's called "fishing" and not "catching." Well, when you lose it feels like gambling. When you don't lose it feels like you earned something. Sorta like capitalism!

Gamble or no, Super Bowl grid pools are essential to ensure group of people who don't really care about football take an interest in the game. So think of it as an investment in a good time that will cost a group of friends net zero dollars to implement. Even for the losers, it's win-win.

This week I got an invitation to a party that made me wince. The nut:

Let's make it clear that this Superbowl Party is in no way about watching the Superbowl, but all about getting appropriately day-drunk while consuming copious amounts of greasy food. (I will have the game on the tv for those who are interested).

That parenthetical scared me worst, as it was an honest attempt to reassure those of us with red, beating hearts that "the Superbowl" would be invited to its own party. So I sat this particular host down a few days later and explained this concept of a grid pool, assuring her that it is indeed a form of gambling. With her interest piqued, I offered instructions.

1. Get a poster or a sheet of paper, the bigger the funner. Draw a grid: 11 vertical lines forming squares across 11 horizontal lines. Leaving ragged edges, like tic-tac-toe, beats a closed-ended spreadsheet. We have to deal with enough of those in our society already.

2. Write BALTIMORE across the top and SAN FRANCISCO along the side. (If you're reading this in a year other than 2013, choose the appropriate cities. Maybe in 2025 your axes will read MEXICO CITY and SAN DIEGO, if either of those towns get teams.)

3. Stick it on a wall, preferably. To give it that authentic feel, decorate it with pictures of ravens and old prospectors. Your grid should look a little like this, but with a DIY flair. It ain't a marriage certificate. Freelance a little.

4. Have everyone put in a dollar or two or five for each of the 100 squares on the grid. Everyone needs some skin in the game. It's Super Bowl party FICA. You don't need to buy 10 squares, but you should have to buy at least one. Today, we are all in on the action.

5. Once all the squares have been signed, write the digits 0-9 randomly above the 10 columns and along the 10 rows. You can make this cute by drawing numbers out of a hat or you can make it nerdy by visiting a random number generator. Or make it cute and nerdy by printing out the first 2,000 digits of pi and letting a baby pick a starting point to pull digits.

6. Divide the money evenly into four piles of $25 or $50 or $125 or whatever. After each quarter, give a moneypile to the person whose square corresponds with the last digit of the teams' scores. If San Francisco's winning 7-6 after the first quarter, the lucky square at the intersection of SF 7 and Baltimore 6 will get a moneypile. Same square wins again if the score is 17-16 at halftime, and so on.

Ideally what you get is multiplied interest every time the score is in doubt, especially near the end of a quarter. Say our Ravens, losing 17-16, are driving with a minute to go before the half. Now a chorus of the SF 7 row is now screaming at the television, all for different results: Ravens 6 wants to see the 49ers' defense hold, Ravens 9 wants to see a field goal, Ravens 3 wants a touchdown, Ravens 4 wants a touchdown with a two-point conversion, Ravens 2 wants a touchdown with a failed conversion. Meanwhile SF 4, Ravens 6 is quietly hoping for a pick-six. (It can happen! It has!) I remember the absurdity of cheering when Steve McNair missed Frank Wycheck on a two-point conversion attempt after the Titans scored at the end of the third quarter in Super Bowl XXXIV. I had St. Louis 6 and Tennessee 6; the conversion would've put Tennessee at 8. Instead I won $50. A a few days later, on the north side of Chicago, I handed exactly $50 to a ticket scalper and got to see Beck. Grid-pool fate makes dreams come true.

The pool can stagnate if defenses dominate. So add a twist, if you must. First quarter, final digits of team scores. Second and third quarters, combined digits of team scores wins. (For instance SF 28, Baltimore 16 would pay the SF 0, Baltimore 7 square.) Fourth quarter, last digits of the final score.

If the game goes into overtime, you're down to side bets, which you can now make, since four people in the room are feeling flush. And by now a bunch of disinterested football tourists have been properly sucked into the game, cheese-dip hangovers be damned. It's not a gamble, son. Grid pool's a lock.